This invention is concerned with improvements in or relating to the diagnosis of disease particularly, but not exclusively infectious diseases caused by intracellular micro-organisms; as well as being practised on humans in appropriate cases these methods may be practised on animals.
For example, conjunctivitis and keratitis are common eye diseases and may be for example viral, bacterial or chlamydial in causation. The serious eye disease Trachoma is a chlamydial kerato-conjunctivitis. The viruses are commonly adenoviruses or herpes simplex virus.
In the diagnosis of these diseases it is important to have a rapid and reliable method of distinguishing between the chlamydial, adenoviruses and herpes simplex virus infections.
Among the in vitro diagnostic methods available are the direct demonstration method and the culture method. In the direct demonstration method, for example, intact conjunctival cells are smeared onto a slide and assayed by for example immunofluorescent staining techniques. In the culture method, for example, the cell structure in a conjunctival tissue sample is first broken down and then the sample is inoculated onto an appropriate cell culture in order to allow infecting micro-organisms multiply; the culture may be treated with ionizing radiation or chemically treated so that any infecting microorganism grows at the expense of retarded cell growth. The incubated sample is then assayed for the presence of micro-organism for example by immunofluorescent staining.
It will be appreciated that both direct demonstration and culture methods require collection of a conjunctival tissue sample directly from the eye. Typically for the direct demonstration method the conjunctival sample is obtained by scraping with a sharp instrument or spatula. In the culture method the sample is obtained by the use of a cotton wool swab, and this also can sometimes be used for the direct demonstration method. In any event these procedures are uncomfortable for the patient and sometimes may not be particularly efficient.
It is an object of the invention to provide an improved probe adapted to collect a conjunctival tissue sample from the eye for assay by for example the culture or direct demonstration method.
The direct demonstration and culture methods are also applicable to cervical or urethral tissue samples. Again cotton wool swabs have been used for obtaining such genital samples, for example mounted on a flexible wire, and these devices are expensive, and again rather inefficient.
The invention provides a probe adapted to collect a mucous tissue sample in vivo comprising (a) a handle portion; (b) a body portion; (c) means for collecting tissue comprising a plurality of slots provided in the body portion, the slots having outer edge portions; and (d) means for scraping tissue into the slots, said tissue scraping means being provided by the outer edge portions of the slots. The width of each slot between its outer edge portion is for example 0.25-0.75 mm.
The probe may be of integral construction or alternatively the body portion could be provided as an item separate from the handle portion with a releasable connection between them so that a single handle portion could be used with a plurality of successive disposable body portions.